Sugar alcohol may unlock better diagnosis for thirst disorders

This study looked at whether a substance called mannitol can trigger the release of copeptin, a hormone marker, to help tell apart two conditions that cause excessive thirst and urination: primary polydipsia and arginine vasopressin deficiency. In the first part, healthy adults received mannitol or a placebo to see if it works. In the second part, patients with these conditions received mannitol to compare their copeptin responses. The goal is to improve diagnosis without complex tests.